Improvement in pneumatic railway-signals



w. near-use". Pneumatic Railway SignalsL Pa tented Feb. 17,1874.

IInrrnn STATES PATENT OFFICE.

"VILLIAM ROBINSON, OF BELLEFONTAINE, OHIO.

lMPROl/EMENT IN PNEUMATIC RAILWAY-SIGNALS.

Specification forming part of Letters Patent No. 147,692, dated February17, 1874; application filed November 9, 1872.

To all whom it may concern.

Be it known that I, WILLIAM ROBINSON, of Bellefontaine, in the county ofLogan and State of Ohio, have invented an Improved PneumaticRailway-Signal and Telegraph, of which the following is a specification:

. My apparatus is constructed with two cylinders, connected by a pipe,and provided with pistons which fit the said cylinders with sufficientaccuracy to cause a movement of one piston to move the other by the.motion of the ,air at ordinary atmospheric pressure.

In applying the apparatus to signaling on rail'ways, I employ a rockinglever or other suitable form of key which will be actuated by a tappetor projection 011 the pilot of the locomotive or other. part of apassing train. To each piston or piston -rod is attached a signal orsignalscreen, and the parts are so arranged that as the train enters thepart of the road which the signals are designed to protect, it will, bymoving one of the workinglevers in one direction, unmask the signal atthat end, while this movement will,by the motion of the air in thecylinders and their connectingpipe, cause a corresponding movement ofthe piston and screen at the other end, so as to unmask the othersigma-1.. As the train leaves the section of road to be protected itrocks the second lever in the opposite direction, imparting a reversemovement to the pistons, and thereby again covering or screening thesignals simultaneously.

Figure 1 is a plan illustrating the application of my invention to arailway-track. Fig. 2 is a vertical longitudinal section on the line .1;as, Fig. 1. Fig. 3 is an elevation of one cylinder, signal-lantern andscreen, detached.

A A represent a pair of cylinders, open at bottom, and connected attheir upper ends by an air-pipe, B, of any requisite length. This pipe Iprefer to place under ground, but it may be support ed on posts, ifdesired. In the cylinders A A are fitted pistons O O,connected, by rodsD D, to the extremities of arms E E, which project from rock-shafts F F.rock-shafts are also provided with levers G G the-ends 1 2 of whichproject nearly horizontally in opposite directions, and are formed topermit the passage of a suitable tappet, and

The

cause the latter to leave in a depressed posi tion that end or arm ofthe lever which it strikes last. Hrepresents a suitable tappet .or armprojecting from the pilot of a locomo track to be protected. The tappetH passes the depressed end 2 of the lever G without effect, but onreaching the end 1 depresses this, and thus, by the connections F E D L,draws down the screen M, and exposes the signal K. This action alsodraws down the piston O, producing a slight exhaust through the air-pipeB, and causing the piston O to be thrown up by atmospheric pressure,thus elevating the screen M above the signal K, and unmasking thelatter, at the same time throwing the end 2 of the lever G up, and theend 1 down. The parts remain in this position, leaving the signalsexposed, as long as the train or locomotive remains on the track betweenthem. As the tappet H passes the lever G it throws down the end 2thereof, drawing the screen M down in front of the signal K, and, by themeans already explained, elevating the screen M, so as to mask thesignal K. The same efiect would be produced if the locomotive shouldback 01f over the lever G. \Vhichever end of the lever is last depressedremains down until it is thrown up by the depression of the opposite endof the same or of the other lever. The depression of the end 1 of eitherlever exposes both signals, and the depression of the end 2 masks both.Either piston, whether moved up or down, actuates the other piston byforcing or exhausting the air, as the case may be.

Parts of my invention are applicable to producing signals at a distancefor other purposes than that above described. I I

I am aware that mechanical railway signals have been patented in whichtwo signals are exposed and masked simultaneously at the ends of a curveor point of danger, and that operated by the double-ended levers G G, in

the broad idea of transmitting motion through combination with theair-cylinders A A and a pipe by means of air is not new. Theseconnecting-pipe B, substantially as herein defeatures of my invention,separately oonsidscribed,for the purpose specified.

ered, are therefore disclaimed. T The following is claimed as new,namely: ROBINSOIM The pair of pistons O G, with their rods D Witnesses:

D, having the signal screens L M L M OGIAVIUS KNIGHT,

attached thereto, and counterbalanced and H. PEAR-CE.

